Close space vapor transport of gallium nitride in vacuum

GaN synthesized by close space vapor transport in vacuum using GaN powder as the source material is reported. According to X-ray diffraction measurements, samples grown onto sapphire substrates are polycrystalline with the wurzite structure, while those grown onto fused silica substrates are amorphous. Scanning electron microscope and energy dispersive spectroscopy results show that the surface of the samples is composed of rounded droplets of GaN. Room temperature photoluminescence shows near band-edge emission and a broad defect band. Possible mechanisms allowing the deposition of GaN from the vapors of GaN powder are discussed.

► GaN compound was prepared using a CSVT configuration in vacuum.
► Catalytic effect of liquid gallium in the decomposition of the N2 molecules does not seem to explain the formation of GaN in these conditions.
► Intense luminescence in these GaN thin films was observable with the naked eye.